Machining centers are often used for metal and wood cutting or milling processes to shape a workpiece into the desired configuration. The process of forming a finished product can require several distinct types of cutting or milling requiring a variety of different tool and a variety of relative motions between the workpiece and the tool. To provide for the substantially continuous processing of the workpiece, machining centers often include automatic tool changers (ATC) that are capable of changing out the in-use tools.
Often, some of the tools within the ATC are live tools. Live tools provide a rotating cutting tool in additional to the translational motion of the tools themselves. Live tools may be mechanically driven live tools or may be fluid driven live tools. In the case of mechanically drive live tools, the machining center may operate a centralized motor that is mechanically engaged with the live tool when the live tool has been selected for use. Thus, knowledge of the operating conditions of the live tool must be inferred from the operation of the centralized motor within the ATC.
In the case of fluid driven spindles, the centralized drive motor may not be required at all. Within relying upon the wired communication between a controller of the machining center and the ATC, there may not be any way to fully monitor the operation of a fluid driven spindle in-use within a machining center set up for mechanical live tools. In other words, current machine control systems may be unable to sufficiently determine the live tool's operating condition for access control or other reasons. Even when powered through the machine control system, the tool's operating condition is monitored indirectly from afar, such as through a centralized motor. This indirect monitoring can lead to inaccuracies caused by time lag or a break in the system. Therefore there is a need for a system that allows for local, accurate monitoring of the operation of live tools. Preferably, there is a need for a monitoring system that may be applied somewhat universally to existing live tools.